Humidity-controlled gas-borne matter collection device

ABSTRACT

A system includes a device for collecting gas-borne matter therein and a humectant provided external to the device for maintaining a desired humidity level for collected matter in the device.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

The present application claims the benefit under 35 U.S.C. §119(e) ofU.S. Provisional Patent Application No. 60/855,868 filed Nov. 1, 2006.

The following applications are incorporated by reference herein in theirentirety, including the drawings, claims, description, and abstractthereof: U.S. Provisional Patent Application No. 60/855,868; U.S. patentapplication Ser. No. 10/857,290; U.S. patent application Ser. No.10/857,240; U.S. Provisional Patent Application No. 60/473,841; U.S.patent application Ser. No. 11/348,222; U.S. patent application Ser. No.11/348,051; and U.S. patent application Ser. No. 10/808,114.

BACKGROUND

The present invention relates generally to the field of airborne mattercollection devices.

Air sampling devices are generally used to determine the quantity andtypes of matter present in a gas (e.g., air or other gaseousatmospheres). For example, in a factory where materials are used thatmay be detrimental to human health, it may be desirable to determine theamount and types of matter present in the atmosphere so that factoryworkers are not exposed to unsafe or undesirable levels of airbornematerials. In other examples, air sampling devices may be used in avariety of environments, including, but not limited to, officebuildings, houses, hospitals, clean rooms, or outdoors.

Sampling devices conventionally include a collection device (e.g., aparticle impaction device, microscope slide, petri dish, or otherdevice) for collecting and retaining matter included in the gas beingsampled. In use, the sampling device draws a gas (e.g., air) toward thecollection device. Matter (e.g., viable and/or non-viable matter)included in the gas impacts a substance or material (e.g., a collectionmedium) provided on or in the collection device, where the matter isretained until analysis can be performed. One known type of collectiondevice is a cassette or cartridge type sampling device, such as theAir-O-Cell product manufactured by Zefon International, Inc. of Ocala,Fla.

One difficulty associated with the use of some known collection devicesis that the collection devices may become contaminated with continueduse. For example, after sampling is complete, the collection medium(e.g., agar medium) is removed from the collection device and thecollection device is cleaned. Remnants of past samples and media mayremain after cleaning, which may affect results of subsequent sampling.

Another difficulty with conventional collection devices is that moisturelevels may be uncontrolled near the collection medium. It is desirable,especially in the case of living organisms, that the sampled matter bemaintained at an appropriate moisture level such that the sample neitherdehydrates nor is over-hydrated to the point that the organisms continueto grow. In either case, such situations may lead to inaccurateinformation concerning the sampled matter.

One potential solution is the use of a dessicant to remove moisture inthe vicinity of the collection medium. However, dessicants tend tosimply dehydrate the collected matter instead of maintaining humidity ata desired level, which may not be suitable for living organisms.

It would be desirable to provide a relatively simple and inexpensivesystem for controlling the moisture level of sampled gas-borne matter toprevent dehydration and growth (i.e., to maintain the moisture level atan equilibrium level that is suitable for maintaining the sampleswithout promoting growth). It would also be desirable to provide asystem for storing and/or shipping sampled matter that maintains themoisture level of the sampled material.

SUMMARY

An exemplary embodiment relates to a system that includes a device forcollecting gas-borne matter therein and a humectant provided external tothe device for maintaining a desired humidity level for collected matterin the device.

Another exemplary embodiment relates to a system for controlling thehumidity in a gas-borne matter collection device. The system includes amember configured for coupling to a gas-borne matter collection deviceand a material provided within the member for maintaining apredetermined level of humidity within the collection device.

Another exemplary embodiment relates a system that includes a housingconfigured for selective coupling to a gas-borne matter collectiondevice. A humectant material is provided within the housing formaintaining a predetermined level of humidity within the collectiondevice. The housing includes a structure for physically containing thehumectant material while allowing two-way vapor transmission between thehumectant material and the collection device.

Another exemplary embodiment relates to a system for collecting viablegas-borne matter that includes a sampling cassette including at leastone inlet, at least one outlet, and a plate provided intermediate theinlet and outlet. A substance is provided on the plate for capturingviable matter carried in a gas drawn through the at least one inlet. Acap is configured for coupling to the cassette, and a humectant isprovided in the cap for maintaining a predetermined level of humiditywithin the cassette. The system also includes a membrane providedbetween the humectant and the cassette that allows gas and vapor to movebetween the substance and the humectant. The humectant is configured toregulate the water activity level such that viable matter is maintainedin a living state without promoting growth of such viable matter.

Another exemplary embodiment relates to a system that includes acontainer, a gas-borne matter collection device provided within thecontainer, and a humectant material provided within the container. Thehumectant material is configured to maintain a humidity level within thecontainer and within the gas-borne matter collection device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a collection device in the form of asampling cassette according to an exemplary embodiment.

FIG. 2 is an exploded perspective view of the collection device shown inFIG. 1.

FIG. 3 is another exploded perspective view of the collection deviceshown in FIG. 1.

FIG. 4 is a cross-sectional view of the collection device shown in FIG.1, the cross-sectional view being taken across line 4-4 in FIG. 1.

FIG. 5 is a perspective view of a cap coupled to the collection deviceshown in FIGS. 1-4 according to an exemplary embodiment.

FIG. 6 is a perspective view of the cap shown in FIG. 5.

FIG. 7 is an exploded perspective view of the cap shown in FIG. 5.

FIG. 8 is another exploded perspective view of the cap shown in FIG. 5.

FIG. 9 is a perspective view of a pouch for holding the collectiondevice according to an exemplary embodiment.

FIG. 10 is another perspective view of the pouch shown in FIG. 9.

FIG. 11 is a schematic diagram illustrating a system for maintaininghumidity in a collection device according to an exemplary embodiment.

FIG. 12 illustrates a system for maintaining humidity in a collectiondevice according to another exemplary embodiment.

FIG. 13 illustrates a system for maintaining humidity in a collectiondevice according to another exemplary embodiment.

FIG. 14 illustrates a system for maintaining humidity in a collectiondevice according to another exemplary embodiment.

FIG. 15 illustrates a system for maintaining humidity in a collectiondevice according to another exemplary embodiment.

DETAILED DESCRIPTION

With reference to FIGS. 1-4, a collection device or apparatus 10 isshown according to an exemplary embodiment that is configured for usewith a pump or other air sampling device (not shown). Collection device10 is shown in the form of a cassette or cartridge, although variousconfigurations for may be used according to other exemplary embodiments.

According to an exemplary embodiment, collection device 10 is configuredfor use with a sampling device that draws air or other gases through thecollection device (e.g., using an impeller, blower fan, or other type offan or pump) to collect matter contained in or carried by the air orgases. According to other exemplary embodiments, other configurationsfor the collection device may be used, which may or may not require theuse of a sampling device. One exemplary embodiment of such a samplingdevice is described in U.S. patent application Ser. No. 10/857,240,filed May 28, 2004, the entire disclosure of which is incorporatedherein by reference.

Collection device 10 includes a top or upper portion 20, a bottom orlower portion 40, and a sampling plate or slide 50. Collection device 10may be disassembled by decoupling top portion 20 and bottom portion 40to allow removal of plate 50 after sampling has been completed. Topportion 20 and bottom portion 40 may be made from a variety ofmaterials, including polymeric, metal, ceramic, glass, or othermaterials suitable for use in a collection device.

According to an exemplary embodiment, collection device 10 has a sizeand shape configured for coupling with a sampling device. For example, arubber grommet tubing or other feature of the sampling device may coupleto collection device 10 to relatively securely retain collection device10 in place.

According to the exemplary embodiment shown in FIGS. 1-4, collectiondevice 10 has a relatively cylindrical shape. According to otherexemplary embodiments, other sizes and shapes for the collection devicemay be used. For example, according to another exemplary embodiment, acollection device may have a rectangular solid or cubic shape.

Top portion 20 includes an inlet 22 that defines an aperture or opening24 through which gas is drawn during sampling. According to an exemplaryembodiment, the size of aperture 24 defined by inlet 22 narrows from atop portion 26 to a bottom portion 28 of inlet 22. Aperture 24 has agenerally rectangular shape when viewed in the axial direction. The size(e.g., area) of the rectangle decreases from top portion 26 to bottomportion 28 in a substantially continuous manner. According to anexemplary embodiment, the width of aperture 24 (e.g., the longer side ofthe rectangle) remains constant between top portion 26 and bottomportion 28 while the length (e.g., the shorter side of the rectangle)decreases with increasing distance from top portion 26. As shown in FIG.4, a cross-sectional view of inlet 22 taken along line 4-4 in FIG. 1shows that aperture 24 has a generally trapezoidal shape when viewed inthe longitudinal direction due to the decreasing size of aperture 24with increasing distance from top portion 26. Aperture 24 thus narrowsto form a slit 34 in a surface 21 of top portion 20.

According to another exemplary embodiment, both the length and width ofthe rectangle forming the aperture decrease with increasing distancefrom the top of the inlet. According to other alternative embodiments,the shape of the inlet and/or aperture may differ. For example, anaperture may have a generally circular, square, oval, or other shapewhen viewed in the axial direction. Such inlets and/or aperturesaccording to alternative embodiments may or may not decrease in areawith increasing distance from the top of the inlets. For example, wherean aperture and/or inlet is provided with a generally circularcross-section viewed in the axial direction, the aperture and/or inletmay resemble a funnel (e.g., the area decreases with increasing distancefrom the top of the inlet) or may resemble a cylinder (e.g., the areadoes not decrease with increasing distance from the top of the inlet).Any of a variety of shapes and configurations may be provided for theaperture and/or inlet according to various other embodiments, and theshape, size, and other characteristics may be optimized for a particularapplication.

Bottom portion 40 of collection device 10 includes an outlet or exitport 42 defining an aperture or opening 44 through which air is drawnduring sampling. A beam or bar 46 is provided across aperture 44 and isintegrally formed with a surface 45 provided in bottom portion 40. Beam46 acts as a stop to prevent objects from being inserted throughaperture 44, which might otherwise collide with and damage or destroyplate 50.

According to an exemplary embodiment, outlet 42 has a generally circularshape when viewed in the axial direction and tapers from a largerdiameter to a smaller diameter with increasing distance from a surface45 provided in bottom portion 40. According to alternative embodiments,the size and/or shape of outlet 42 may differ. For example, according toanother exemplary embodiment, the outlet may have a generally square oroval shape when viewed in the axial direction. Further, the outlet mayor may not taper along its length.

While collection device 10 is shown as having a single outlet and asingle inlet, according to other exemplary embodiments, any number ofoutlets and inlets may be provided in a collection device having any ofa variety of different configurations (e.g., one outlet may have arelatively circular opening while a second outlet may have a relativelyrectangular opening, etc.). A sampling plate or slide may have differentsampling mediums (e.g., suspension media) provided in different areassuch that a different sampling medium is provided adjacent each of theplurality of inlets.

When collection device 10 is assembled, a portion of top portion 20 isinserted within bottom portion 40 such that a first rim or surface 30provided on top portion 20 abuts a first rim or surface 41 provided onbottom portion 40 and a second rim or surface 32 provided on top portion20 abuts a second rim or surface 43 provided on bottom portion 40. Plate50 is provided intermediate a top portion 20 and a bottom portion 40 ofcollection device 10 (and hence between inlet 22 and outlet 42). A topsurface 52 of plate 50 is provided adjacent or proximate slit 34 formedin bottom surface 21 of top portion 20. According to other exemplaryembodiment, other ways of connecting the top portion to the bottomportion may be utilized (e.g., glue, fasteners such as screws and bolts,welding, etc.).

To secure plate 50 in relation to inlet 22 and slit 34, projections orprotrusions 36 extend outward from bottom surface 21 of top portion 20.Plate 50 is positioned between projections 36 such that projections 36prevent lateral movement of plate 50. Additionally, corners 56 of plate50 are received within cutouts 38 included in second rim 32 of topportion 20 to further restrict movement of plate 50 and to secure plate50 in a relatively fixed relationship to inlet 22 and slit 34. Whileplate 50 is shown as having a particular shape in the accompanyingFIGURES, according to other exemplary embodiments, the plate or slidemay have any of a variety of sizes, shapes, and/or configurations (e.g.,oval, circle, hexagon, etc.), which may be chosen based on any of avariety of factors (e.g., required size of sampling area,manufacturability, cost, etc.).

Other means of securing the plate in place may be utilized according toother embodiments. For example, either projections or cutouts may beomitted from the collection device. In another example, where a platehaving a different size or shape is utilized, a different number ofcutouts and/or projections may be utilized. In yet another example,neither cutouts nor projections are provided, and the plate is securedin place by a different type of feature or structure. In yet anotherexample, the plate may be glued (e.g., using an adhesive) orultrasonically welded in place. Any feature or structure that retainsthe plate in place may be utilized according to various embodiments.

While the FIGURES illustrate a collection device 10 that includes a topportion 20 that is inserted into a bottom portion 40, according toanother exemplary embodiment a bottom portion may be inserted into a topportion. According to another embodiment, neither of the top and bottomportions are inserted into each other, and coupling of the top portionand bottom portion is accomplished by any of a variety of other methods.According to various other embodiments, the top and bottom portions maybe secured together using adhesives, ultrasonic welding or sealing, ascrew-type arrangement, a snap-fit type arrangement, or any othersuitable means.

Plate 50 may be made of any suitable material, including glass, porousglass fiber filters, ceramic, porous plastic, metal (e.g., aluminum,steel, etc.), or any other suitable material (e.g., a porous rigidmaterial). According to an exemplary embodiment, plate 50 is made ofglass and has a generally rectangular shape. Plate 50 is relatively thin(e.g., between approximately 0.001 and 0.125 inches), although thethickness may vary in alternative embodiments. For example, the platemay be formed to have a thickness similar to that of conventionalmicroscope slides. Other configurations may also be used for plate 50.For example, the plate may be made of a polymeric material and/or may beformed in the shape of an octagon, triangle, square, circle, oval, orany other suitable shape (e.g., cup-shaped, dish-shaped, etc.).

According to an exemplary embodiment, collection device 10 is adisposable or non-reusable type collection device (i.e., collectiondevice 10 is intended as a single-use type component that is discardedafter use). According to other exemplary embodiments, collection device10 may be a reusable type collection device (e.g., the plate may becleaned and re-inserted into the collection device or the plate may bereplaced with a new plate). After sampling is complete, collectiondevice 10 is disassembled to remove plate 50 from collection device 10so that the matter retained in substance 54 may be quantified, tested,or otherwise analyzed. One advantageous feature of using a disposablecollection device is that cleaning of the plate (e.g., removal of thesuspension medium (e.g., substance 54) and captured viable matter anddeposition of new or fresh suspension medium) is eliminated. A relatedadvantageous feature of using a disposable collection device is thaterrors in sampling due to contamination of the suspension medium and/orto variations in application of new suspension medium material to theplate may be reduced or eliminated. According to another exemplaryembodiment, plates (e.g., glass slides, etc.) may be provided asseparate components for use in a collection device and sold separatelyfrom the collection device.

FIG. 4 shows a cross-sectional view of collection device 10 taken in thelongitudinal direction along line 4-4 in FIG. 1. Gas flow throughcollection device 10 is indicated generally by dashed arrows. As shown,gas is drawn into collection device 10 through inlet 22. The velocity ofthe air increases as it approaches bottom portion 28 of inlet 22 due tonarrowing of aperture 24. The gas then travels around plate 50 andthrough outlet 42. At least a portion of the gas-borne matter drawn intoinlet 22 is captured by a substance or material 54 (e.g., a suspensionor transport medium) provided on plate 50 when the gas changes directionto travel around plate 50.

Substance 54 is provided on top surface 52 of plate 50 and is alignedwith slit 34 such that matter carried in a gas impacts substance 54 whengas is drawn through inlet 22 during sampling. In this manner, gas-borneviable and/or non-viable matter may be captured by substance 54.

Substance 54 may be any suitable collection medium according to variousexemplary embodiments, non-limiting examples of which are described inU.S. patent application Ser. No. 10/808,114, filed Mar. 24, 2004, theentire disclosure of which is incorporated herein by reference.According to one exemplary embodiment, substance 54 is configured tomaintain viable matter (e.g., biological organisms such as mold spores,bacteria, skin cells, anthrax, viruses, insects and insect parts, andother viable matter) in a living state without promoting growth of suchviable matter. For example, substance 54 is configured to providehydration for viable matter included therein to prevent the viablematter from drying out and/or dying when retained within substance 54.

According to an exemplary embodiment, substance 54 is configured tomaintain viable matter in a living state for at least a predeterminedamount of time (e.g., between approximately 1 and 14 days). For example,mold spores captured in the substance 54 may be kept alive in substance54 for between approximately 2-7 days before growth may appear. Thespecific amount of time viable matter may be kept alive may depend on anumber of factors, including the type of viable matter (e.g., moldspores, viruses, bacteria), the composition of the substance, thetemperature of the sample, and other factors.

To prevent contamination of substance 54 with nutrients or otherdevelopment-promoting materials during shipping and/or storage,collection device 10 may be sealed. For example, collection device 10may be vacuum sealed and/or may include elements that cover inlet and 22and outlet 42 to prevent introduction of any airborne nutrients.According to an exemplary embodiment, stickers or labels are provided tocover openings 24 and 44 during shipping and storage. According toanother exemplary embodiment, caps or plugs may be provided to coveropenings 24 and 44. Such stickers, labels, caps, or plugs are removedbefore sampling to allow the flow of gas through collection device 10,and may be replaced after sampling is completed to prevent contaminationof the sample. Collection device 10 may also be shipped and/or stored ina sealed (e.g., vacuum sealed) pouch or container to further preventcontamination and reduce drying of the substance that acts as asuspension medium.

When sampling is completed, collection device 10 may be disassembled toremove plate 50 (and hence the suspension medium and captured viablematter). Plate 50 may be removed from collection device 10 immediatelyafter sampling is complete, or may remain in the collection deviceduring shipping of the collection device to a remote location (e.g., alab) or during storage. It may be desirable to seal the collectiondevice until it is desired to remove the plate from the collectiondevice (e.g., by re-attaching a label, sticker, plug, or cap overapertures 24 and 44 to prevent contamination of substance 54 and viablematter captured therein).

To remove viable matter from substance 54, a liquid (e.g., water,peptone solution, etc.) is utilized. According to an exemplaryembodiment, substance 54 is removed from plate 50 (e.g., by scraping)and placed in a liquid to separate the substance 54 from the viablematter. According to another exemplary embodiment, the entire plate 50,including substance 54, is placed in a liquid to remove substance 54from plate 50 and the viable matter from substance 54. According toanother exemplary embodiment, liquid may be introduced into thecollection device 10 to remove substance 54 from plate 50 and the viablematter from substance 54. In any of these embodiments, the container orcollection device holding the liquid may be vibrated or shaken (e.g.,using a vortexer or other device, by hand, etc.) to hasten separation ofviable matter from substance 54. According to still another exemplaryembodiment, no vibration or shaking may be used, and the substance 54will dissolve in water or another liquid, after which the water may besampled.

With reference to FIGS. 5-8, a member or element 60 (shown in the formof cap or container) configured for use with a collection device 10 isshown according to an exemplary embodiment. Member 60 is configured tomaintain a humidity or moisture level within the collection device 10.One advantageous feature of the exemplary embodiments shown in FIGS. 5-8is that the water activity level (aW %) within the collection device 10is regulated near a predetermined level, which may improve the accuracyof sampling by maintaining an appropriate sample size. For example,using a material such as a humectant, collected viable matter ismaintained in a living state without promoting growth of such viablematter. The aW % is the amount of water in a substance available for useand as those reasonably skilled in the art would be aware, anappropriate low level will stop organisms from growing while enoughmoisture would still be present to maintain the organisms in a livingstate.

According to an exemplary embodiment, the member 60 may be provided tocover aperture(s) 24 and/or 44 and may be in a shape similar tocollection device 10. Member 60 includes a top portion or part 70, abottom portion or part 80, a material 90 (e.g., a humectant), a firstmembrane or filter 92, and a second membrane or filter 91. When member60 is assembled, a portion of top part 70 is inserted within bottom part80 such that a first rim or surface 71 provided on top part 70 abuts afirst rim or surface 81 provided on bottom part 80 and a second rim orsurface 72 provided on a top part 70 abuts a second rim or surface 82provided on bottom part 80. Top part 70 and bottom part 80 may be madefrom a variety of materials, including polymeric, metal, ceramic, glass,or other materials suitable for use in a collection device.

The top part 70 may include a hollow area or space 75 formed or definedby the second rim 72 and a top surface 73. The material 90 may beinserted into the hollow area 75. The second membrane 91 may be providedadjacent or in contact with the humectant and the second rim 72. Thefirst membrane 92 may be configured to be provided adjacent or incontact with the second membrane 91 and may be of the same approximateshape.

The bottom part 80 may include a first hollow area or space 85 formed bythe first rim 81 and a second hollow area or space 86 formed by thesecond rim 82. The first rim 82 may be configured to be providedadjacent or in contact with the second membrane 91. When the member 60is assembled the first hollow area 85 may be configured to allow thesecond rim 72, the material 90, the first membrane 92 and the secondmembrane 91 to be partially enclosed within the inner area of the member60.

According to an exemplary embodiment as shown in FIGS. 5-8, the member60 may be configured to cover aperture 24 of a collecting device 10. Thebottom part 80 may be inserted within top portion 20 such that the firstrim 81 abuts a first rim or surface 23 provided on top portion 20 andthe second rim 82 abuts a second rim or surface 25 provided on topportion 20.

Any of a variety of materials may be selected for use as material 90.According to an exemplary embodiment, material 90 is a humectant havinga predetermined water activity level (aW %). Material 90 will absorb orrelease water until an equilibrium point is reached in the collectiondevice and in the cap or member 60. The humectant may be chosen so thata water activity level that is optimum for biological materials ismaintained. According to an exemplary embodiment, the humectant 90 ischosen to maintain a water activity level between approximately 30-75%.According to a particular exemplary embodiment, a water activity levelof approximately 65% is used. According to other exemplary embodiments,the water activity level may be between approximately 23% and 81%. Theuse of humectant materials has the advantageous result of maintainingliving material within collection device 10 while preventing or limitinggrowth of the material.

According to an exemplary embodiment, the material 90 is a humectantformed from a mixture of a salt that is hydrated with a liquid (e.g.,water) to provide the desired water activity level. According to anexemplary embodiment, the humectant comprises a mixture of water and asalt selected from the following: Calcium Bromide, Lithium Iodide,Potassium Acetate, Potassium Fluoride, Sodium Iodide, PotassiumCarbonate, Magnesium Nitrate, Sodium Bromide, Cobalt Chloride, PotassiumIodide, Strontium Chloride, Sodium Nitrate, Ammonium Chloride, AmmoniumSulfate.

According to the embodiment of FIGS. 5-8, the first membrane 92 allowsvapor to pass between the material 90 and the collection device 10. Thefirst membrane 92 contains and separates the material 90 from collectiondevice 10, and may be formed of any material that allows for two-wayvapor transmission. According to an exemplary embodiment, the membraneis made from a porous plastic material (e.g., polypropylene,polyethylene, nylon, polycarbonate, polyvinylchloride, etc.). Accordingto other exemplary embodiments, the membrane may be made of a metal(e.g., an aluminum member with apertures or holes provided therein), aporous paper material, or any other suitable material. The thickness,shape, size, porosity and other characteristics of the first membrane 92may vary according to various exemplary embodiments.

A second membrane 91 may also be provided that provides furthercontainment and separation of material 90 from collection device 10. Thesecond membrane 91 may be comprised of a spunbonded olefin such asTyvek® or another appropriate material such as those described withrespect to membrane 92. The thickness, shape, size, porosity and othercharacteristics of the second membrane 91 may vary according to variousexemplary embodiments.

According to an exemplary embodiment as shown in FIGS. 9-10, member 60may be packaged in a pouch 100 that serves as a vapor barrier so theexposure to moisture during shipment and storage may be limited. Thepouch 100 may be manufactured of a foil material or other suitablematerial. According to an exemplary embodiment, the pouch is formed offoil (e.g., aluminum foil) that is coated with another material (e.g.,mylar, polyester, polypropylene, etc.). According to another exemplaryembodiment, the pouch is formed of a metal-impregnated polymer (e.g.,aluminum-dusted polypropylene).

The member 60 may be placed in the pouch 100 and the open end 102 closedor sealed by any standard method including but not limited to being heatsealed. The pouch 100 may also comprise a closing element 101 that maybe resealed such as two plastic strips that fit into each other on theinner surface of the pouch 100. After the heat seal is broken, theclosing element 101 may be used to reseal the pouch 100.

Collection device 10 may be utilized in a variety of different mannersaccording to various exemplary embodiments. For example, in a firstexemplary embodiment, collection device 10 may include a plate similarto plate 50 described above. The plate may be a clean substrate made ofglass or another suitable material. Air sampling may be performed insuch a manner that particles or other matter carried in the air areimpacted directly onto the clean plate (i.e., the plate has nosuspension material or other substance provided thereon). After samplingis completed, the plate may be directly sampled to an agar or othergrowth medium for culturing.

According to another exemplary embodiment, collection device 10 mayinclude a plate similar to plate 50 described above, which may either beclean or may have a substance such as substance 54 or another substanceprovided thereon for capturing airborne matter. Airborne matter sampledonto the plate may then be suspended by adding a liquid such as water orpeptone water to the collection device and retaining it therein (e.g.,by plugging the inlet and outlet, etc.). Subsequent to sampling andsuspension, the collection device may be drained and the liquid may beutilized with any of a variety of growth mediums for a variety ofdifferent tests (e.g., agar culturing, ELISA testing, PCR testing,etc.).

Various modifications may be made to collection device 10 that may allowfor optimization for a particular use. For example, while the size ofthe opening at the bottom portion 28 of inlet 22 may be changeddepending on the size and/or type of materials being sampled. Inapplications in which mold spores will be sampled, for example, theopening may have a length of approximately 0.6 inches and a width ofapproximately 0.030 inches. For a collection device that will be used inthe collection of nanoparticles, the width of the bottom portion 28 ofinlet 22 may be between approximately 0.001 and 0.005 inches. Virussampling may utilize a width of the bottom portion 28 of inlet 22 may bebetween approximately 0.005 and 0.020 inches. Bacteria sampling mayutilize a width of the bottom portion 28 of inlet 22 may be betweenapproximately 0.015 and 0.025 inches. According to other exemplaryembodiments, the size of the bottom portion of the opening may beoptimized for the particular use and may have a different shape and/orsize.

According to another exemplary embodiment, the material (e.g.,humectant) for maintaining the humidity level of the sampled matter maybe provided such that the material is not provided in a cap coupled to acollection device. In this manner, the humidity level of the sampledmatter can be maintained at a desired level without the use of a capsuch as that shown in FIG. 6.

FIG. 11 is a schematic diagram of a system 200 that includes a containeror housing 202 that includes a first compartment or portion 206 and asecond compartment or portion 208. The container 202 (and other suchcontainers as will be described below according to other exemplaryembodiments) may be used for storage and/or shipping of the collectiondevices, and according to an exemplary embodiment are configured so thatthey may be sealed in vapor-tight fashion (e.g., the interior of thecontainer will have an environment substantially unaffected by thehumidity level external to the container when the container is sealed).Alternatively, the entire container may be sealed within a vaporproofpouch or container.

The first compartment 206 is separated from the second compartment 208by a structure such as a wall or divider 204. All or a portion of thewall 204 may be configured to allow two-way transmission of vaporbetween the first compartment 206 and the second compartment 208 (asillustrated by arrows in FIG. 11). For example, all or a portion of thewall 204 may be formed of a membrane material similar to those describedabove with respect to membranes 91 and 92. According to other exemplaryembodiments, all or a portion of the wall may include apertures or holesformed therein to allow two-way transmission of vapor.

According to an exemplary embodiment, a material 210 (e.g., a humectant)is provided within the first compartment 206. A container 212 mayoptionally be provided for containing or storing the material 210. Forexample, FIG. 13 illustrates a system 300 in which the cap 60illustrated in FIG. 6 is provided in a first compartment 306 of acontainer 302 and is separated from a second compartment 308 by a wall304. Of course, those reviewing this disclosure will appreciate that theparticular configuration of the container 212 may vary according toother exemplary embodiments.

A collection device 220 is provided in the second compartment 208.According to one embodiment as shown in FIG. 12, the collection deviceis similar to that shown in FIG. 1. According to other exemplaryembodiments, the form of the collection device may differ.

One advantageous feature of the embodiment shown in FIGS. 11-12 is thatthe containers 202, 302 provide a humidity-controlled environment inwhich the collection devices may be stored and/or shipped (before and/orafter sampling has been completed). That is, because the wall dividingthe compartments allows for two-way transmission of vapor, anequilibrium point may be reached within the containers 202, 302 that issuitable to maintain the collected matter at a desired humidity level(or, where the collection devices have not yet been used for sampling,the collection devices may be maintained at a desired humidity level).

It should be understood that various modifications may be made to theembodiments shown in FIGS. 11-12. For example, according to an exemplaryembodiment, a single humectant material may be provided to control thehumidity for a plurality of collection devices. There are a number ofways that such an embodiment may be accomplished. In one system 400shown in FIG. 13, a humectant 410 may be provided in a compartment 406of a container 402. The compartment 406 is defined by walls 404 (all ora portion of which may be configured to allow for two-way transmissionof vapor) with a plurality of collection devices 420 provided in anadjacent compartment 408.

In another system 500 shown in FIG. 14, a humectant 510 may be providedin one compartment 506 defined by walls 504 (all or a portion of whichmay be configured to allow for two-way transmission of vapor). Theremainder of the container 502 may be subdivided into additionalcompartments (e.g., compartments 508, 510, 512, and 514 shown in FIG.14). Such compartments may be adjacent the compartment 506 in which thehumectant is provided and/or adjacent to other compartments. Walls 509,511, and 513 separating adjacent compartments may be configured to allowfor two-way transmission of vapor according to an exemplary embodiment.In this manner, humectant material may be contained in one area whileproviding humidity-controlling functionality for various separatecompartments within the container. As shown in FIG. 14, compartments mayinclude one or more collection devices.

According to other exemplary embodiments, humectants and collectiondevices may be provided in a single compartment, as shown in FIG. 15, inwhich a system 600 includes a container 602 in which a humectant 610 anda collection device 620 are provided in a single area. In the embodimentshown in FIG. 15, there are no internal subdivisions of the container602 into separate compartments, although it should be understood that ina container having multiple compartments, one or more of suchcompartments may include both collection devices and humectant (and thehumectant may or may not be stored in a container of its own).

The size, shape, location, and configuration of the various containersand compartments in such containers may also vary according to numerousother exemplary embodiments, and such alternative configurations areintended to fall within the scope of the present disclosure.

As those of skill in the art will appreciate, various advantages may beobtained using a collection device and/or suspension medium as describedherein. For example, it is intended that because the collection devicemay be provided in a single-use form, there is no need to reload thecollection device with a slide having new media provided thereon. It isalso intended that the need to clean the slide or plate between uses isalso eliminated. Further, it is intended that the risk ofcross-contamination is reduced since the collection device is packagedin a relatively sterile environment and the slides or plates are notre-used. Contamination from the open environment may also be reduced,since the collection device may be sealed prior to shipping to the enduser.

Other advantages may also be obtained. The collection device may beprovided such that it is relatively compact and lightweight, which mayallow it to be used in relatively tight or confined spaces. Theconfiguration of the collection device may allow the device to be usedwith relatively low backpressure as compared to other devices which mayrequire relatively large vacuum pumps to pull air through them.

The sampling medium (e.g., suspension medium) may be provided such thatit need not be refrigerated, which may allow for simpler transport andstorage. It is also intended that the sampling medium will have arelatively long shelf life as compared to other sampling media, and thatit may be utilized to suspend the sample in a liquid or to archive thesuspended solution. Further, it is intended that the sampling medium mayact to eliminate or reduce the occurrence of dessication and destructionof organisms or other viable matter.

The construction and arrangement of the elements of the collectiondevice as shown in the preferred and other exemplary embodiments isillustrative only. Although only a few embodiments have been describedin detail in this disclosure, those skilled in the art who review thisdisclosure will readily appreciate that many modifications are possible(e.g., variations in sizes, dimensions, structures, shapes andproportions of the various elements, values of parameters, mountingarrangements, use of materials, orientations, etc.) without materiallydeparting from the novel teachings and advantages of the subject matterrecited herein. For example, elements shown as integrally formed may beconstructed of multiple parts or elements, the position of elements maybe reversed or otherwise varied, and the nature or number of discreteelements or positions may be altered or varied. It should be noted thatthe elements and/or assemblies of the system may be constructed from anyof a wide variety of materials that provide sufficient strength ordurability, including any of a wide variety of moldable plasticmaterials in any of a wide variety of colors, textures and combinations.The order or sequence of any process or method steps may be varied orre-sequenced according to alternative embodiments. Other substitutions,modifications, changes and omissions may be made in the design,operating conditions and arrangement of the preferred and otherexemplary embodiments without departing from the scope of the presentinvention.

1. A system comprising: a sampling cassette having a plate providedtherein for collecting gas-borne matter; and a humectant providedexternal to the sampling cassette for maintaining a desired humiditylevel for collected matter in the sampling cassette.
 2. The system ofclaim 1, wherein the humectant has a water activity level of betweenapproximately 23% and 81% and comprises water and a salt selected fromthe group consisting of Calcium Bromide, Lithium Iodide, PotassiumAcetate, Potassium Fluoride, Sodium Iodide, Potassium Carbonate,Magnesium Nitrate, Sodium Bromide, Cobalt Chloride, Potassium Iodide,Strontium Chloride, Sodium Nitrate, Ammonium Chloride, and AmmoniumSulfate.
 3. The system of claim 1, further comprising a member coupledto the ice sampling cassette, the member containing the humectant. 4.The system of claim 3, wherein the member comprises at least one porousmembrane for physically separating the humectant from the samplingcassette and configured to allow water vapor to flow between thesampling cassette and the humectant.
 5. The system of claim 3, whereinthe member is a container comprising an upper portion and a lowerportion that are removably coupled together.
 6. The system of claim 1,further comprising a container, wherein the device sampling cassette andthe humectant are provided within the container.
 7. The system of claim6, wherein the container comprises a first compartment and a secondcompartment, the device sampling cassette provided in the firstcompartment and the humectant provided in the second compartment,wherein the first compartment is separated from the second compartmentby a membrane that is configured to allow water vapor to travel betweenthe first compartment and the second compartment.
 8. A system forcontrolling the humidity in a gas-borne matter collection samplingcassette, comprising: a member configured for coupling to a gas-bornematter collection sampling cassette; and a material provided within themember for maintaining a predetermined level of humidity within thecollection sampling cassette.
 9. The system of claim 8, wherein thematerial is a humectant having a water activity level of betweenapproximately 23% and 81% and comprising water and a salt selected fromthe group consisting of Calcium Bromide, Lithium Iodide, PotassiumAcetate, Potassium Fluoride, Sodium Iodide, Potassium Carbonate,Magnesium Nitrate, Sodium Bromide, Cobalt Chloride, Potassium Iodide,Strontium Chloride, Sodium Nitrate, Ammonium Chloride, and AmmoniumSulfate.
 10. The system of claim 8, wherein the member comprises anupper part and a lower part that are removably coupled to each other.11. The system of claim 8, wherein the material is physically separatedfrom the collection sampling cassette by a porous membrane.
 12. A systemcomprising: a housing configured for selective coupling to a gas-bornematter collection sampling cassette; and a humectant material providedwithin the housing for maintaining a predetermined level of humiditywithin the collection sampling cassette; wherein the housing comprises astructure for physically containing the humectant material whileallowing two-way vapor transmission between the humectant material andthe collection sampling cassette.
 13. The system of claim 12, whereinthe humectant material has a water activity level of betweenapproximately 30% and 75%.
 14. The system of claim 12, wherein thestructure comprises a membrane.
 15. The system of claim 12, furthercomprising a collection sampling cassette, wherein the housing and thecollection sampling cassette are provided in a container.
 16. The systemof claim 12, further comprising a collection sampling cassette, whereinthe housing and the collection sampling cassette are provided in a vaporimpermeable pouch.
 17. A system for collecting viable gas-borne matter,the system comprising: a sampling cassette comprising at least oneinlet, at least one outlet, and a plate provided intermediate the inletand outlet; a substance provided on the plate for capturing viablematter carried in a gas drawn through the at least one inlet; a capconfigured for coupling to the cassette; a humectant provided in the capfor maintaining a predetermined level of humidity within the cassette;and a membrane provided between the humectant and the cassette thatallows gas and vapor to move between the substance and the humectant;wherein the humectant is configured to regulate the water activity levelsuch that viable matter is maintained in a living state withoutpromoting growth of such viable matter.
 18. The system of claim 17,wherein the humectant has a water activity level of betweenapproximately 23% and 81% and comprises water and a salt selected fromthe group consisting of Calcium Bromide, Lithium Iodide, PotassiumAcetate, Potassium Fluoride, Sodium Iodide, Potassium Carbonate,Magnesium Nitrate, Sodium Bromide, Cobalt Chloride, Potassium Iodide,Strontium Chloride, Sodium Nitrate, Ammonium Chloride, and AmmoniumSulfate.
 19. The system of claim 17, wherein the sampling cassettecomprises a top portion connected to a bottom portion.
 20. A systemcomprising: a container; a gas-borne matter collection device in theform of a sampling cassette provided within the container; and ahumectant material provided within the container, the humectant materialconfigured to maintain a humidity level within the container and withinthe gas-borne matter collection device.
 21. The system of claim 20,wherein the humectant material is provided within a housing configuredfor coupling to the gas-borne matter collection device.
 22. The systemof claim 20, wherein the container includes a first portion and a secondportion, and wherein the gas-borne matter collection device is providedin the first portion and the humectant material is provided in thesecond portion.
 23. The system of claim 22, wherein the first portion isseparated from the second portion by a structure configured to allowtwo-way water vapor transmission.
 24. The system of claim 22, whereinthe container further comprises a third portion, the third portionincluding at least one of a humectant and a collection device.